Often forgotten in the general history of prisons, the Directorial period constitutes a significant phase in the transition between the prisons of the Old Regime, and prisons specifically for punishment introduced in 1791. This article will examine the prison system under the Directory through a case study of Nantes. Presenting itself as reformist, the post-Thermidorian regime found itself in grave difficulty when faced with the management of prisons. Combining a mixture of social issues, public order, and political repression, the prison was at the heart of the construction of the republican edifice. From the years IV to VIII, prisons became the subject of a discourse celebrating the closing of the unhealthy cloisters of the previous years and the introduction of the prison reform of 1791. In fact, the so-called « Republican » prison policy masked a hybrid practice at the crossroads of the heritage of the prisons of the Old Regime, the permanence of extraordinary revolutionary practices, and the development of the prison for punishment.